Device for removing fused slags on slabs

ABSTRACT

This invention relates to a device for removing fused slags on slabs wherein &lt;-shaped cutters with the front center thereof being the apex are disposed on the front and rear positions of a tool rest being vertically movable with a required spacing and being close to the undersurface of the slab, respectively. At least the rear cutter is biased upwardly by a spring mounted in the lower portion of the tool rest. At the same time the shear point in the rear cutter is made to be somewhat higher than that of the front cutter in order to cut out the fused slags deposited on the undersurface of the slab on a transferring roller table with a prescribed length. If it is arranged in such a way that a water-cooling means for water-cooling the deposited portion of the fused dross is disposed before and behind the above device for removing fused slags on slabs, respectively, to cut off the cured dross, the fused slags can more effectively be removed.

TECHNICAL FIELD

The present invention relates to a device for cutting off and removingfused slags deposited on the undersurface of a slab produced when stripsteel stocks shaped by means of continuous casting facilities and thelike are fusion-cut to prepare a slab of a prescribed length by the useof a torch.

TECHNICAL BACKGROUND

For example, belt-shaped steel stock produced by means of continuouscasting facilities are usually fusion-cut to obtain a slab having aprescribed length. In this case, fused slags produced at the time ofcutting out a slab are deposited on the undersurface of the slab so thatso-called torch dross is formed on such slab.

If a slab on which fused slags are deposited is subjected to hot rollingwith the fused slags, there arise intrusive flaws by means of rollingrollers, and lamination flaws on the surface of rolled products and thelike, and therefore it is required to remove such fused slags in thetransferring process of the slab.

Conventional methods for removing such fused slags as mentioned aboveare divided broadly into two categories, i.e., a method for blowing offmolten slags in accordance with scarfing and a method for cutting slagsoff by means of cutters. Relating to the latter method, a device forcutting off slags by the use of cutters is disclosed in, for example,Japanese Utility Model Laid-open No. 64139/1979.

The device described in the above Utility Model application isconstructed in such a manner that respective cutters are divergentlyplaced on from the front center to the rear opposite sides of a toolrest being vertically movable by means of a fluid pressure cylinder witheach required angle with respect to the advancing direction as well aswith each required spacing. At the same time these cutters aredivergently arranged towards the rear of the tool rest so as to overlapan end portion of each cutter with that of the cutter adjacent thereto,and projection levels of the respective cutters are gradually loweredfrom the cutter disposed on the central part of the tool rest towardsthe cutters disposed on divergent opposite sides of the tool rest.

However, the device as set forth above has a disadvantage in that sincethe respective cutters are arranged as mentioned above, if end portionsof a slab to be processed are warped widthwise, fused slags on thewarped portions cannot sufficiently be cut out. Besides there is alsosuch a disadvantage in that at the time when a cutter abuts against aslab to be processed, large impact force is applied to the cutter sothat life of such cutter is shortened.

SUMMARY OF THE INVENTION

Accordingly, an object of the present invention is to provide a devicefor removing fused dross by which disadvantages involved in theconventional art as mentioned above, can be eliminated, In the presentinvention the slab is successively cut at every part thereof inaccordance with an angle of sweepback of the cutters, thereby to reducethe impulsive force which acts on the cutters so that the life thereofcan be prolonged. Also, where a slab is warped widthwise, fused slagscan smoothly and positively be cut out successively over the whole widthof the slab in a step-by-step manner.

The characteristic features of the present first invention resides inthat <-shaped front and rear cutters with a front center thereof beingthe apex of said <-shaped cutters and disposed front and rear positionsof a tool rest with the apex facing in a direction opposite to thetransfer direction, respectively, at least a spring mounted in the toolrest for biasing the rear cutter in an upward direction, and a shearpoint of the rear cutter projects higher than that of the front cutter.

Another mode of the present first invention is that a <-shapedstationary front cutter with the center thereof as the apex, middlecutters each consisting of a cutter part biased by a spring disposedwith a required spacing from the front cutter and overlapping with thefront cutter and each stationary cutter part placed adjacent to theoutside of the middle cutter part, and rear cutters each consisting of acutter part biased by a spring disposed similarly to that of the middlecutters and overlapping with the stationary cutter part positionedbefore the middle cutter part and each stationary cutter part placedadjacent to the outside of the middle cutter part are provided on a toolrest being vertically movable, respectively, and the shear point in themiddle cutter part is made to be somewhat higher than that of eachstationary cutter part.

One one hand, heretofore, removal of fused dross on a continuously castslab or the like after cutting off the same has usually been carried outby a manner as illustrated in FIG. 1. Namely, FIG. 1 is an explanatoryview illustrating a method for removing fused dross according to aconventional example in which a slab 1 after it was cut off istransferred on a transferring table consisting of a plurality of tablerollers 3 in a direction indicated by an arrow A as shown in FIG. 1. Onthe undersurface in a cut-off part of the slab 1, fused dross 2 havebeen deposited, and to remove such fused dross, cutters 4 for removingfused dross are provided usually below the path line (pL) in avertically movable manner. And when the slab 1 on which the fused dross2 is deposited is transferred to a prescribed position, the cutter 4 forremoving fused dross is raised simultaneously with a cutter pedestal 5by means of a cylinder 6 to urge and abut the cutter 4 for removingfused dross upon the undersurface of the slab 1, whilst a pinch roll 7contacts with the surface of the slab 1 so that the fused dross 2 issheared and removed. After completion of shearing and removing of thefused dross, the cutter 4 for removing fused dross is lowered by meansof the cylinder 6 and the cutter 4 returns to a position below the pathline (pL). In FIG. 1 it is to be noted that two removal means for fuseddross are provided, since the fused dross is deposited on theundersurface in both the front and rear ends of a slab. However, whenfused dross is removed by such a manner as described above and since asurface temperature of the slab 1 in the end face thereof at the time ofremoving the fused dross is generally a high temperature such as 700° C.and higher, the fused dross cannot completely be removed due to tackresistance or the like of the slab. Furthermore, when the removal offused dross is incomplete, the unremoved portion is transferred to thefollowing step as it is so that when such slab is rolled to obtain aproduct, the unremoved portion remains as flaws in the product.Therefore such defective parts are ordinarily cut off and removed. As aresult, there arise such problems as dropping of the yield and the like.Under the circumstance, the existence of such fused dross is generallydetected in a transferring step of the slabs so that if an unremovedportion is found, removal of the fused dross is again carried out inaccordance with any manner before such slab is rolled.

As mentioned above, in a conventional example, fused dross of a slab hasbeen subjected to a removal process of fused dross when the surface ofthe slab is at a high temperature so that the fused dross can not becompletely removed. For this reason, it has been required to detect theexistence of fused dross in the transferring process of slabs. Moreoverprocesses for handling slabs have been disrupted according to thefrequency of rejected product.

Accordingly, an object of a second embodiment of the present inventionis to eliminate the disadvantages as described above, and specificallyto provide a method for removing fused dross on slabs. In the secondembodiment a device therefor is provided in which a deposited portion ofthe fused dross is previously water-cooled and then; the fused dross iseasily and completely removed, hence, unlike conventional examples thereis no need of any detection for the existence of fused dross in itstransferring step and results in a reduction of the frequency of flawsin the products after such slabs are rolled.

Namely, the second embodiment of the present invention is characterizedby subjecting a slab such as a continuously cast slab or the like tocontinuous gas cutting on a hot slab transferring table, thereafterwater-cooling a deposited portion of the fused dross on the undersurfaceof the slab in the cut-off portion thereof, adjusting a temperature atthe end face of the aforesaid slab in the aforesaid deposited portion ofthe fused dross to 650° C. or less, and then shearing and removing thedross.

Furthermore the second embodiment of the present invention ischaracterized, as another mode thereof, in that a gas cutting means forsubjecting a slab such as a continuously cast slab or the like tocontinuous gas cutting on a hot slab transferring table line is followedby a shearing and removing means for cutting out the fused drossdeposited on the undersurface of the slab in the cut-off portionthereof, and water-cooling means for water-cooling the deposited portionof the fused drops on the slab are disposed before and behind theshearing and removing means for the fused dross, respectively, wherebythe device is arranged such that the fused dross is sheared and removedby means of the shearing and removing means.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an explanatory view illustrating a method for removing fuseddross according to a conventional example;

FIG. 2 is a schematic side view illustrating an example of a device inaccordance with the present invention;

FIG. 3 is a schematic planar view showing an arrangement of cutters on atool rest;

FIGS. 4 and 5 are schematic planar views each showing another example ofthe arrangement of cutters on a tool rest;

FIG. 6 is a schematic side view illustrating another mode of the presentinvention;

FIG. 7 is a schematic planar view showing an arrangement of cutters on atool rest;

FIG. 8 is a schematic layout illustrating an example of a device forembodying a second embodiment of the present invention;

FIGS. 9(a) and 9(b) are side and planar views showing an example of awater-cooling device, respectively;

FIGS. 10, 11, 12 and 13 are explanatory views illustrating respectiveprocesses in case of removing fused dross according to the secondembodiment of the present invention; and

FIG. 14 is a graphical representation illustrating a relationshipbetween a temperature in a slab end face and a dross removal rate.

THE MOST PREFERRED MODES FOR EMBODYING THE INVENTION

The embodiments of the present invention will be described hereinbelowby referring to the accompanying drawings in which FIGS. 2-5 illustratethe embodiments of the present first invention, respectively.

In FIG. 2, reference numeral 21 designates a roller table fortransferring a slab 22 of a prescribed length to, for example, a hotmill, and at the lower part, being an optional position between therollers, of the roller table 21, a tool rest 24 being moved verticallyby means of a fluid pressure cylinder 23 which is disposedperpendicularly to the roller table 21.

Furthermore, as shown also in FIG. 3, on the top of the tool rest 24, acutter 25 having, e.g., a <-shape section in the plane and being formedsuch that the front (the inlet side of the slab 22) center thereof isthe apex and which diverges continuously towards the opposite ends ofthe cutter with an angle θ of sweepback of, for instance, around 3-10degrees, preferably around 5 degrees, is fixed and held such that theshear point of the cutter is placed with the face upward by means of aholder 24a secured to the tool rest 24.

At the rear position (the outlet side position of the slab 22) of thecutter 25, another cutter 26 having the same shape as that of the cutter25 and being arranged to have a required spacing with respect to thecutter 25, preferably in parallel, is maintained such that the shearpoint of the cutter 26 is positioned with the face upward by means ofthe holder 24a. Moreover a suitable abutting force is given to maintainthe cutter 26 with respect to the undersurface of the slab 22 by meansof a spring 27 installed on the lower part of and inside the holder 24a.

The shear point of the cutter 26 is set higher than that of the frontcutter 25 by, for example, around 3-5 mm. Accordingly, when the slab 22to be processed is warped in the width direction, these cutters arearranged in such that the shear point of the rear cutter 26 abutsagainst the undersurface of the slab 22, whereby a fused slag 22a on theundersurface of the slab 22 can be cut out, even if the shear point ofthe front cutter 25 does not abut against the bottom of the slab 22.

In addition, another spring may also be installed on the undersurface ofthe front cutter 25.

Furthermore it is preferably that the rear cutter 26 is divided intoplural parts as shown in FIG. 4, and springs are installed on the bottomof the divided cutters 26, respectively, whereby these cutters are madeto sufficiently cope with the widthwise or lengthwise warp of the slab22. In this case, it is desirable to make each shear point of thedivided cutters 26 higher by several mm.

As an alternative example for dividing the rear cutter 26, the dividedcutters may be arranged such that they are successively shiftedrearwardly from that positioned innermost to those positioned outermostas shown in FIG. 5.

As a matter of course, the device according to the present invention canalso be applied to the case where scales on the top and bottom faces aswell as both of the side faces of the slab 22 are removed. In this case,it may be arranged such that two pairs of the tool rests 24 eachprovided with the cutters 25 and 26 are placed opposite to one anotheron the top and bottom faces as well as both the side faces of the slab22, respectively.

Moreover, since the roller table 21 for transferring the slab 22 isrotated and controlled in normal and reverse directions of the rollertable to reciprocate the slab 22 for removing fused slags or scales, thetool rests each provided with the cutters 25 and 26 are disposed on thefront and rear positions in the advancing direction of the slab 22symmetrically to each other with a required spacing.

The present first invention is composed, as mentioned above, such thatin order to cut out fused slags on a slab in the transferring process ofthe the slab of a prescribed length, <-shaped cutters with a frontcenter thereof being the apex are disposed on the front and rearpositions of a tool rest and are vertically movable with a requiredspacing; and respectively, at least the rear cutter is maintained at alower position with respect to the tool rest through a spring, and atthe same time the the shear point of the rear cutter is made to besomewhat higher than that of the front cutter. Accordingly there is notsuch fear that fused slags extending over all the region in thewidthwise direction of the undersurface of the slab are cut out at thesame time by means of both the cutters, and the slab can be successivelycut out at every part in accordance with the angle of sweepback of thecutters. Therefore it does not occur that a large impulsive force isapplied to the cutters so that the life of the cutters can be prolonged.

Furthermore, in the case where a slab is warped widthwise, such fusedslags which could not be cut out by means of the front cutter cansmoothly and positively cut out by means of the rear cutter.

FIGS. 6 and 7 are views for illustrating another embodiment of thepresent invention, respectively.

In FIG. 6, reference numeral 31 designates a roller table fortransferring a slab 32 fused with a prescribed length to, for example, ahot mill; and at the lower part, being an optional position between therollers, of the roller table 31, a tool rest being moved vertically bymeans of a fluid pressure cylinder 33 is disposed perpendicularly to theroller table 31.

Furthermore, as shown also in FIG. 7, on the top of the tool rest 34, afront cutter 35 having, e.g., a <-shape section in the plane and beingformed such that the front (the inlet side of the slab 32) centerthereof the apex and which diverges towards the opposite ends of thecutter with an angle θ of sweepback of, for instance, around 3-10degrees, preferably around 5 degrees if fixed, and held such that theshear point of the cutter is placed with the face upward by means of aholder 34a secured to the tool rest 34.

In addition, middle and rear cutters 36 and 37 being arranged so as tohave a required spacing with respect to the front cutter 35, preferablyin parallel thereto, respectively, and which diverge successivelytowards the opposite ends of the front cutter in the rear directionthereof while these middle and rear cutters which are overlapped witheach other are positioned with the face upward by means of the holder34a.

Among the middle and rear cutters 36 and 37, parts of cutters 36a and37a overlapping with their own front cutters, respectively, aremaintained by receiving a suitable abutting force on the undersurface ofthe slab 32 by means of a spring 38 installed on the lower part of andinside the holder 34a, respectively.

In respect to the shear points of the cutter parts 36a and 37a in therespective middle and rear cutters on which the spring 38 is installed,the shear point of a cutter positioned before another cutter, e.g., theshear point of the cutter part 36a is set higher than that of the frontcutter 35 by, for instance, around 3-5 mm, and further the shear pointof the cutter part 37a is set higher than that of a stationary cutterpart 36b of the cutter 36 in by, for example, around 3-5 mm.Accordingly, when the slab 32 to be processed is warped widthwise, thesecutters are arranged such that the shear points of the rear cutter parts36a and 37a abut against the undersurface of the slab 32, whereby afused slag 32a on the undersurface of the slab 32 can be cut out, evenif the shear point of the front cutter does not abut against the bottomof the slab 32.

As illustrated in FIG. 7 by means of dot and dash lines, cutters 39 toeach of which a spring 38 is provided may be disposed behind thestationary cutter parts 37b of the rear cutters 37 with a requiredspacing, preferably in parallel to each other.

Furthermore, it is preferable that the cutter parts 36a and 37a (alsothe cutters 39) provided with springs 38, respectively, are divided intoplural parts in order to sufficiently cope with variations in warp ofthe slab 32.

As a matter of course, the device according to this embodiment can alsobe applied to the case where scales on the top and bottom faces as wellas both the side faces of the slab 32 are removed. In this case, it maybe arranged such that two pairs of the tool rests 34 each provided withthe respective cutters 35, 36, 37 and the like are placed opposite toone another on the top and bottom faces as well as both the side facesof the slab 32, respectively.

Moreover, since the roller table 31 for transferring the slab 32 isrotated and controlled in normal and reverse directions of the rollertable to reciprocate the slab 32 for removing fused slags or scales, thetool rests each provided with the cutters 35, 36, 37 and the like aredisposed on the front and rear positions in the advancing direction ofthe slab 32 symmetrically to each other with a required spacing.

The present embodiment is composed, as set forth above, such that inorder to cut out fused slags on a slab in the transferring process ofthe slab of a prescribed length, a <-shaped stationary front cutter withthe front center thereof being the apex; middle cutters each consistingof a cutter part provided a spring disposed with a required spacing fromthe front cutter and overlapping with the front cutter and eachstationary cutter part placed adjacent to the outside of the cutterpart; and rear cutters each consisting of a cutter part provided with aspring disposed similarly to that of the middle cutters and overlappingwith the stationary cutter part positioned before the cutter part andeach stationary cutter part placed adjacent to the outside of the cutterpart having a spring are provided on a tool rest being verticallymovable, respectively, and projection level of the shear points, in thecutter part having a spring is made to be somewhat higher than that ofeach stationary cutter part positioned before this cutter part.Accordingly, there is not such fear that fused slags extending over allthe region in the widthwise direction of the undersurface of the slabare cut out at the same time by means of these cutters, but the slab cansuccessively be cut out at every part in accordance with the angle ofsweepback of the cutters. Therefore a large impulsive force is notapplied to the cutters so that the life of the same can be prolonged.

Furthermore, when a slab is warped widthwise, such fused slags whichcould not be cut out by means of the front cutter can smoothly andpositively be cut out successively in a step-by-step manner by means ofcutter parts overlapping with those positioned before the same among themiddle and rear cutters.

FIGS. 8-14 are views for illustrating a second embodiment of the presentinvention, respectively.

First, FIG. 8 is a schematic layout showing an example of the device forembodying the second embodiment of the present invention in which slabssuch as continuous cast pieces and the like are continuously cast bymeans of a continuous casting machine 8, and such slabs are continuouslycut off by means of each gas cutting apparatus (not shown) in each table9 by a torch. Each slab after cutting off the same is transferred toeach of transferring tables 11 and 12 from each torch delivery table 10,and such slab is transferred in a direction indicated by an arrow B bymeans of each of the transferring tables 11 and 12.

Next, in these transferring tables 11 and 12, means 15a and 15b forshearing and removing fused dross are provided in order to eliminate thefused dross of the slab after it was cut off, and water cooling means13a and 13b are disposed before and behind the shearing and removingmeans 15a and 15b for fused dross, respectively. Such shearing andremoving means 15a and 15b for fused dross may be composed in any typeof a means so far as the means is constructed such that fused dross onthe undersurface of a slab can be sheared to remove the fused dross inthe cut portion of the slab. In general, however, as shown in FIG. 1, itis sufficient if a pedestal 5 for supporting a cutter 4 for removingfused dross in the lower part of a path line is constructed so as tofreely ascend and descend by means of a cylinder 6. Furthermore, each ofthe water cooling means 13a and 13b may be constructed as any type of ameans so long as the means can cool a fused dross deposited portion downto 650° C. or less in the cut portion of a slab, but usually it ispreferable to compose the means as shown in FIGS. 9(a) and 9(b).

Namely, FIGS. 9(a) and 9(b) are a side view and a planar view eachshowing an example of a water cooling means in which a plurality ofsprinkler nozzles 14 are opposed to a cut-off portion 1a of a slab 1transferred by means of each table roller 3 in a transferring table, andthe sprinkler nozzles 14 are arranged such that cooling water can besupplied thereto through a header 14a. By such arrangement, the coolingwater 14b is sprayed from each sprinkler nozzles 14 so that the fuseddross 2 is instantly cooled. Furthermore the respective sprinker nozzles14 may also be constructed such that they are interlocked with adetecting means for a slab section (not shown), for instance, aphotoelectric tube or the like, and when it is detected that a slab endface stops in place by means of the detecting means, the cooling watercan be sprayed.

In addition, as a result of various experiments in case of removingfused dross, it became clear that since a slab was at a hightemperature, the fused dross could not completely be removed because ofits tack resistance. In this respect, the end face of the slab on whichthe fused dross is deposited is cooled by spraying water thereonto andconsequently, it has turned out that when a temperature at the slab endface is made to be 650° C. or less as shown in FIG. 8, the fused drosscan be substantially completely sheared and removed.

Therefore, in order to completely remove such dross, when the end faceof a slab on which the fused dross is deposited is cooled to atemperature of 500°-200° C., it becomes possible to keep an end facetemperature at the time of removing the dross at 650° C. or less,whereby the dross can completely be removed.

Now, a case where the fused dross on a slab after it was subjected togas cutting is removed will be described hereinbelow through operationalmodes of a device for removing fused dross constructed as describedabove. First, the slab 1 after completing gas cutting is transferred tothe transferring table 12 by way of the torch delivery table 10 and thetransferring table 11, and the slab is stopped on the transferring table12 in a situation shown in FIG. 10. Thereafter cooling water is jettedfrom each sprinkler nozzle 14 of the water cooling means 13b for around5-20 seconds so that the extreme end of the slab 1 is cooled to 650° C.or less. After the extreme end of the slab 1 is cooled by means of thewater cooling means 13b, the slab is backwardly fed on the tables, thedross on the extreme end thereof is cut out by means of the shearing andremoving means 15b. The slab is continued to be backwardly fed, and thenthe slab is stopped at a position illustrated in FIG. 11. Thereafter theslab 1 is again transferred in the direction B, the slab then stops in acondition illustrated in FIG. 12, and the rear end portion of the slabis sprayed by the water cooling device 13a this time to effect coolingthereof. After completing the cooling of the rear end portion of theslab, the slab 1 is again transferred along the direction B, the drosson the rear end portion is removed by means of the shearing and removingmeans 15a, the slab comes to be in a state as illustrated in FIG. 13,and then the resulting slab is transferred to the following steps.

Since the dross portions are sheared and removed after cooling them byway of the above respective steps in second embodiment of the presentinvention, such dross portions can completely be removed so that thereis no trouble in the treatment in the following steps.

If the cooling before shearing and removing of slabs is carried out bysuch manner that a temperature of the slab end face comes to be within arange of 500°-200° C., the slab end face at the time of removing thedross may be cooled so as to be kept at a temperature 650° C. or less.

As described above in detail, the second embodiment of the presentinvention relates to a method in which before the fused dross on a slabis sheared and removed by means of cutters and the like, the fused drossis cooled to make the dross portion brittle by which such portion iseasily sheared, and then the shearing and removing operations arecarried out. As the result, the fused dross can completely be removed bysuch method as stated above. Thus, there are no flaws and the like on aproduct when the billet after it was cut off is rolled in the followingstep. In addition there is no need to detect for the existence of fuseddross in the transferring step, and there is also no fear of causing anytrouble in the other processes.

INDUSTRIAL APPLICABILITY

As mentioned above, the device for removing fused slags on slabsaccording to the present invention is sutable for the installation insteps for processing slabs in an ironwarks as a device for cutting offand removing fused slags on a slab which is obtained by fusing a stripsteel stock fed from continuous casting facilities and the like to aprescribed length by means of a torch or the like.

We claim:
 1. A device for removing fused slags on slabs as said slabsare transferred in a transferring direction, comprising:a tool restwhich is movable in an upward direction perpendicular to saidtransferring direction; at least a front and rear <-shaped cutters witha center of said front and rear <shaped cutter being the apex of said <and disposed in front and rear positions of said tool rest with saidapex facing in a direction opposite to said transferring direction; atleast a spring mounted in said tool rest for biasing said rear cutter insaid upward direction; and a shear point of said rear cutter projectsupwardly somewhat higher than that of the front cutter in order to cutout the fused slags on said slab during the transferring process of theslab of a predetermined length.
 2. A device for removing fused slags onslabs as claimed in claim 1, characterized in that said rear cutter isdivided into plural parts, and a spring is interposed between the undersurface of each plural part and said tool rest.
 3. A device for removingfused slags on slabs as claimed in claim 1, further characterized inthat said rear cutter is divided into plural parts and said plural partsare arranged such that they are successively shifted rearwardly from aninnermost position to an outermost position, and a spring is interposedbetween the undersurface of each plural part and said tool rest.
 4. Adevice for removing fused slags on slabs, characterized in that a<-shaped stationary front cutter shaping the front center thereof beingthe inlet side for a slab as the apex; middle cutters each consisting ofa cutter part installing a spring disposed with a required spacing fromsaid front cutter and lapping over with said front cutter and eachstationary cutter part placed adjacent to the outside of said cutterpart installing a spring; and rear cutters each consisting of a cutterpart installing a spring disposed similarly to that of said middlecutters and lapping over with the stationary cutter part positionedbefore said cutter part one another and each stationary cutter partplaced adjacent to the outside of said cutter part installing a springare provided on a tool rest being vertically movable, respectively; andeach projection level of the share point in a cutter part installing aspring is made to be somewhat higher than that of each stationary cutterpart positioned before the very cutter part in order to cut out thefused slags on said slab in the transferring of the slab of a prescribedlength.
 5. A method for removing fused dross on slabs comprisingsubjecting a slab such as a continously cast slab or the like tocontinuous gas cutting on a hot slab transferring table; thereafterwater-cooling a deposited portion of the fused dross on the undersurfaceof said slab in the cut-off portion thereof; adjusting a temperature atthe end face of said slab in said deposited portion of the fused drossto 650° C. or less; and then shearing and removing said fused dross. 6.A device for removing fused dross on slabs, characterized in that a gascutting means for subjecting a slab such as a continuously cast slab orthe like to continuous gas cutting on a hot slab transferring table lineis followed by a shearing and removing means for cutting out the fuseddross deposited on the undersurface of said slab in the cut-off portionthereof; and water-cooling means for water-cooling said depositedportion on the fused dross on said slab are disposed before and behindsaid shearing and removing means for fused dross, respectively; wherebysaid device is arranged such that said fused dross is sheared andremoved by means of said shearing and removing means.